Yes i know that this happens, but not why. If i click on the "refresh account" button, everything is ok and i can download again for a couple of time.

I asked a third member of this shared account and he says that he just have to refresh the account at the start, but then it works fine. And he is using the same jdownloader 2 version.
Is it possible to refresh the accounts automatically, before stopping the download?

And thanks to you two for the warning. I didnt knew that uploaded dislike multi user accounts, but i am using it for two or three years now and i had no problems with that. Now we are aware that the account could be banned.